How to disable existing Microsoft Outlook signatures using a Group Policy Object

Relevant Products: Signature Manager Exchange Edition | Exclaimer Cloud - Signatures for Office 365

Scenario

You have installed the Signature Manager Exchange Edition or Exclaimer Cloud - Signatures for Office 365, but some of your users still have a signature applied directly by Microsoft Outlook.

You want to disable their existing Outlook signatures and prevent them from setting up signatures in Microsoft Outlook in future.

Resolution

You can disable Microsoft Outlook signatures by creating a Group Policy Object (GPO) on your Domain Controller or another machine responsible for Group Policy configuration.

To disable Microsoft Outlook signatures:

1. Open the Group Policy Management Console by selecting Start > Administrative Tools > Group Policy Management.
   
   
2. Download and extract the appropriate version(s) of the Office Administration Template for the version of Microsoft Outlook you are running in your organization.
   Note: If you are running multiple versions of Outlook in your organization, you should download an Administration Template for each version.
3. Create a new GPO in the required domain. 
   
   
4. Enable appropriate setting(s) for each version of Microsoft Outlook that is used in your environment:
   - Outlook 2013 and 2016

Create a new GPO

To create a new GPO in the domain:

1. Select the required domain.
   
   
2. You can either click on the Action menu and select Create a GPO in this domain > Link it here…
   or right-click the required domain and select Create a GPO in this domain > Link it here…
   
   The example screen displays the right-click menu:
   
   
   The New GPO window is displayed.
3. Specify a name for the new Group Policy Object (GPO) and click OK.
   
   
   
   
4. Right-click the newly created GPO and click Edit.
   
   
5. Navigate to Users Administrative Templates by expanding User Configuration > Policies > Administrative Templates:
   
   
   
   
6. Select Action > Add/Remove Templates…
   
   

7. Select Add and navigate to where the templates for Microsoft Outlook were extracted when creating the GPO:

   Microsoft Outlook Version	Filename
   2013	outlk15.adm
   2016, 2019, Office 365 ProPlus	outlk16.adm

   
   
   Note: Copy outlkxx.admx to C:\Windows\PolicyDefinitions and outlkxx.adml to the appropriate languages folder (that is, C:\Windows\PolicyDefinitions\en-US)
   
   Where xx is 15 for Outlook 2013 and 16 for Outlook 2016.
8. Select Close.
   
   
9. Navigate through and enable the appropriate setting(s) for each version of Microsoft Outlook that is used in your environment:
   - For Microsoft Outlook 2013 and 2016

Microsoft Outlook 2013 and 2016

To enable settings for Microsoft Outlook 2013 and 2016:

1. Expand Microsoft Outlook 2013 (or Microsoft Outlook 2016)> Outlook Options > Mail Format.
   
   
2. On the right-hand side, enable the Do not allow signatures for e-mail messages policy to disable the signatures in Microsoft Outlook 2013 (or Microsoft Outlook 2016):
   
   
   
   Note: Signature options will be disabled and these changes will prevent signatures in Outlook from being applied. However, the existing signature files will not be deleted from client computers – this should be done manually.

Download Office Administration Template

To download the appropriate version(s) of the Office Administration Template for the Microsoft Outlook version you are running in your organisation, use appropriate links below: